Heat exchange device



Oct. 5, 1937.

R. K. D AWSON HEAT EXCHANGE DEVICE FiledvJan. 14, 1955 2 sheets-sheet 1I Get. 5,1937. R. K. DAWSON HEAT EXCHANGE DEVICE 2 Sheets-Sheet 2 FiledJan. l14, 1955 Mp/maf- Patented oct. s, 1931 UNITED sTATEs PATENT OFFICE2,094,77 HEAT EXCHANGE DEVICE Robert K. Dawson,` Guelph, ntarlo, CanadaApplication January 14, 1935, Serial No. 1,800

"rz claims.

to provide a heat transfer device in which agitation of one liquid istransferred to the container of the other liquid for agitating the otherliquid during transfer of heat; also to movably support the containerfor one liquid in the other liquid and subjecting the -other liquid to aback and forth movement foragitating the same,lwhich back and forthmovement produces a corresponding movement of the container andagitation of the liquid therein; also to provide a heat interchanger inwhich a single agitating device serves thev purpose of modifying thetemperature of a liquid and of agitating both the liquid which receivesand that which gives up heat.

Other objects of the invention are to provide an improved milk cooler inwhich milk in cans or containers is agitated by agitation of the coolingwater in which the cans or containers are immersed; also to provide animproved and simplified milk cooler which is emcient and rapid in itscooling action and which is of inexpensive construction and which caneasily be kept clean; also to provide a cooler of this kind in which thecooling coils for the water are moved to provide agitation of the water.

Other objects of the invention will appear from the followingdescription and" claims.

In the accompanying drawings:

Fig. 1 isa fragmentary top plan view of aheat exchange device embodyingthis invention, with the cover removed. Fig. 2 is a sectional elevationthereof on line 2-2, Fig. 1. l i i l Fig. 3 is a fragmentary elevationthereof showing the upper portion of the heat exchange device. Fig. 4 isa transverse sectionalelevation thereof on line 4 4, Fig. l. v

Fig. 5 is a fragmentary sectional view on an enlarged scale, online 5 5,Fig. l.r

Fig. 6 is a fragmentary section online 6 6, Fig. 3.

Fig.f7 .is a fragmentary sectional elevation of (Cl. 31-4) the paddle oragitator of the heat, exchange apparatus.

By way of illustration, my invention is shown in the accompanyingldrawings as applied to a milk cooler of the type in which the usualmetal 5 milk cans are immersed in water in a tank for cooling the milk.It will be understood, however, that it is not intended to limit thisinvention for use in connection with milk coolers, since obviously anyother liquidmay be operated upon by means of the apparatus shown andalso the apparatus may be used for heating liquids as well I.as forcooling the same by merely employing a heating fluid in place of acooling uid.

It is well known that in the transmission of heat from one liquid toanother, the transfer of heat is greatly speeded up if both liquids areagitated or in motion during the transfer of heat, 'o so that the lm ofliquid adjacent to the heat conducting wall is removed by this motionand mixed with the main body of liquid. In many cases, however, it isdiicult to provide agitating means in both liquids, and particularly inthe cooling of milk in milk cans, the employment of agitators in themilk involves not only mechannical difficulties, but also the diicultyof having such agitating means in sterile condition when inserted intothe milk. By means of my improved apparatus, it is necessary only toemploy a single agitating device to impart motion to both liquids.

In the embodiment of the invention Yillustrated in the accompanyingdrawings, one o f the liquids is contained in a suitable tank orcontainer A, the walls'of which may, if desired, be provided with a heatinsulating layer I0. The tank or container shown in the constructionillustrated is of a type adapted to be built into the ground and may bemade of concrete, but it will be understoodthat any suitable' or desiredtype of tank may be employed in place ofthe one shown. The other liquidmay be contained in suitable cans or containers E, which, may, forexample, be in 4the form of milk cans. When my improvements are appliedto a milk cooler, water may be used in the tank A and the milk cans Bare partly immersed inthe water, which may extend approximately to thelevel it shown in Fig. 4, and this level may be controlled by means ofan overflow pipe i2. represents a cover or lid for the tank A. l 50Motion may be imparted to the Vliquid in the tank or container A in 'anysuitable or `desired manner, but for reasons Athat will hereinafterappear such motion is preferably ofl anintermittent or alternatelyreversing type. Any suitable or desired means may be 'provided/for/profducing motion of this kind in the liqid/ in the tank A, and in theconstructiongillustrated, a paddle or oscillatory plate I4 may beemployed, that shown having arms I5 /extending upwardly out of theliquid in the tank and secured to a rock shaftIG suitably ljournalled inbearings I1 which may be mounted on the upper edge of one of the wallsof lthe tank. An upwardly extending rocker arm I8' is also provided onthe shaft I6 and motion may be applied to the arm I8 in any suitable ordesired manner, for example, by means of a pit'man or link I9 pivotallyconnected at one end to the rocker arm I8 and having the other endthereof extending about an eccentric 20 secured to a shaft 2i, see Figs.1 and 4. This shaft may be driven at a relatively low rate of speed inany suitable or desired manner. /In the construction shown, a pulley 24is secured to the shaft 2l and is driven by means of a belt from a smallpulley 25 arranged on a shaft 26. When my invention is applied to a milkcooler, in which the water in the tank A is cooled by means ofrefrigerating apparatus, the compressor of the refrigerating apparatus(not shown) may be operated from the shaft 26. The shaft 25 may be inturn driven from an electric motor 27 by means of a. belt 28 connectingpulleys 29 and 3l] on the motor shaft and the compressor shaft 26respectively. Consequently, when a refrigerating apparatus is employedin connection with my heat exchange apparatus, the oscillatory agitatoror paddle I4 may be readily driven from the compressor of therefrigerating apparatus. When no refrigerating apparatus is provided, asimilar drive for the agitator may be employed, or if desired, othermeans may be used for oscillating the agitator.

Means of any suitable or desired form, may be employed for modifying thetemperature of the liquid in the tank A for the purpose of modifying thetemperature of the liquid in the container B. Such temperature modifyingmeans may be employed Within the tank or container A or outside of thistank. In the particular construction illustrated, I have incorporatedthe temperature modifying means in the paddle or agitator I4, but itwill be understood that it is not intended to limit this invention tothe construction illustrated, in which aatemperature modifying fluid ispassed through a coil of pipe forming a part of or secured to theagitator I4 and preferably, the pipe` forming the coil is attened or ofovalshaped cross section, as lindicated at 32, and this coil may bearranged between two plates 33 and 34 secured together in any suitablemanner, for exampl,'by bolts 35, and the plates, furthermore, arepreferably arranged in heat conducting relation or in contact with thecoil or pipe 32..

coil, extend into immediate proximity to the oscillatory shaft I6 andmay be connected in any suitable or desired manner with the source orsupply of temperature modifying iiuid arranged in xed relation to thetank A. For example, one of the'pipes may extend from the vicinity ofthe shaft I6 to a coil or loop 31, and the other pipe may terminate in aloop 38. Any other means for connecting the movable portions of a pipeor pipes leading to the coil with stationary pipes or conduits may beprovided.

The pipes may be connected in any suitable manner with a source oftemperature modifying fluid. For example, steam, hot water, or otherheating medium may be passed. throughthe pipes and the coil 32, if it isdesired to heat the water in the tank A. Similarly brine or othercooling nuid' may be passed through the pipes, if it is desired to coolthe liquid in the tank A. In the accompanying drawings, I haveillustrated a 'construction by means of which the refrigerant compressedin the refrigerating apparatus (not shown) may be passed through thecoil 32. In this case, one of the pipesv 4 extending to the coil fromthe loop 38 may pass to a suitable expansion valve 4I also carried bythe agitator I4, and the expanded refrigerant may, consequently, pass tothe coil 32 through a pipe or conduit 42 connecting with one end of thecoil 32. The other end of the coil is connected with a pipe 43, which inturn connects with the'coil or loop 31.

In the operation of the apparatus thus far described, the agitator orpaddle I4 will move to a limited extent as `indicated by the full lineand broken line positions of the agitator in Fig. 4. This movement ofthe agitator results in a circulation of the liquid in the tank A sothat liquid iiows past the temperature modifying coil. Fur` thermore,the paddle in its movement forces the liquid in the tank A toward andfrom the containers B for the other liquid. This not only causescirculation of the liquid in the tank A about the Walls of the containerB. but also exerts a certain pressure -or force, alternately in oppositedirections against the cans or containers B. I have found that bymovably supporting the f containers B, the pressure exerted on the sameby the liquid may be used to move the containers B, and this movement inturn produces a movement of the liquid in the containers B whichprovides the necessary agitation. This movement or agitation of theliquid in the containers B continually causes the lm of liquid adjacentto the Walls of the containers B to be mixed with the liquid in theinterior portions of the containers, thus providing a continuous mixingor agitation of liquid in the containers, which results in a very muchmore rapid exchange of heat than takes place in cases where thecontainers B are stationary.

Any suitable or desired means for movably supporting the containers Bmay be provided. In the particular construction shown, tiltable orpivoted supports for the containers B are arranged in the bottom of thetank upon which the` cans or other containers may be placed. Forexample, the support may include a fixed base member arranged on thebottom of the tank A and secured thereto by means of bolts 48 suitablyanchored in the tank bottom. On this base, a movable or tiltable support50 is arranged, which may have a swinging, rocking or pivotal connectionwith the base 41 in any suitable or desired manner. In the constructionillustrated, the base-41 is provided'with a recess or notch 5I intowhich a pivot member or edge 52 of the support 'Ihis provides for aswinging or rocking movement of the support 50 on the base 41 and thismovement may be limited by ears or projections 53 on the support 50which engage with portions 54 at opposite sides of thebase 52. Ifdesired, means may be provided for limiting from the supports and placedon the floor of the suitable threaded engagement with the base 41 andextend loosely through enlarged apertures 56 of the supporting memberl5l). By adjusting these screws, it will be obvious that the movelmentof the support 50 relatively to the base 41 may be regulated as desired,and furthermore, the bolts 55 serve the purpose of holding the support50 in operative relation to the base 5I. On the upper face of thesupport 50, a suitable flange 51 may be provided into which the bottomof the container B may extend for holding the container in operative,position on the supporting member 50.

It will be noted that the pivotal axis about which the supporting membertilts or swings with reference tothe tank extends in a directionapproximately parallel to the shaft I6, or in other words, the pivotalmember 52 extendscrosswise of the .direction of movement of the paddleor agitator I4 and consequently, as the paddle vmoves toward thecontainer B, the liquid will be forced against the side of the containernearestv to the paddle, thus'exerting pressure on this side of thecontainer and forcing the same to swing away from the paddle. As thepaddle moves in the opposite direction, the pressure of water on theportion of the container B nearest to the paddle' or agitator would beless than on the opposite side, so that the container B will be tiltedtoward the paddle. It has been found that this tilting movement of thecontainer B is sufficient to produce a motion of the liquid within thecontainer B in such a manner as to very materially decrease the lengthof time required to effect the transfer of heat from one liquid to the oher. The construction described has the advantage that the paddle oragitator effects an agitation of both of the liquids which are beingtreated and that, consequently, it is unnecessary to provide anyagitator within the containerB. When this invention vi's-used inconnection with milk coolers,

it has the advantage that the time for cooling a can of 'milk is verymaterially reduced, full cooling having been effected with my improvedapplaratus in one third of the time required in similar apparatuswithout agitation. By reducing the (time required for cooling, thedevelopment of 75' they have become'cooled, they may be removed bacteriain the milk is correspondingly reduced. The agitation of the milk in thecontainer B as herein described also avoids any possibility ofcontamination of the milk such as might happen if `an agitator wereinserted into the milk in the can. Furthermo'rait'has been found thatthe agitation of the milk -in the cans which hasbeen described alsoresults in the removal `of odors from the' milk. ,The constructiondescribed also has the advantage that the tankA can easily be keptclean, since the temperature modifying coil 32 is movably mounted, sothat the space between the tank wall and the coil 32 is readilyaccessible for cleaning.l 1

It will be noted that'in Fig. l only two tiltable supports for thecontainers B are provided while two other containers rest directly uponthe floor Vof the tank A. It will, of course, be understood -thecontainers B, but when my invention is used that tiltable supports maybe providedfor all of customary to place the cans' containingA fresh,warm milk on the tiltable supports, and after l perature and to producemovement the containers B can be provided without any additionalexpenditure of power` than that required for agitating only the liquidin the tank A.

I claim as my invention: I

1. A 'heat exchange device including a container for liquid, a containerfor another liquid pivotally mounted on said rst container to oscillateabout a substantially horizontal axis lying approximately in a centralupright plane of the second container and having a heat conducting wall,and means for agtating the liquid in said rst container, said agitationimparting movement to said second container about said axis to producemovement of liquid in said secondcontainer, whereby exchange of heatbetween said liquids through 'a wall of said second container isaccelerated.

2. A heat exchange device including a container for liquid, means formodifying the ternof said liquid, a contanerfor another liquid movablymounted on said first container4 in a substantially balanced position,and having a heat conducting wall, and means for agitating tlie liquidinsaid first container, said agitation imparting movement to said secondcontainer to produce movement of `liquid in said. second container,whereby exchange of heat between said liquids through a wall of saidsecond container is accelerated.

3..A heat exchange device including a container for liquid, a secondcontainer for liquid movably mounted on said rst container in asubstantially balanced position and having a heat conducting wall topermit transfer of heat from the liquid in one container to the liquidin the other container, and means for imparting movement to the liquidin said first container alternately in opposite directions to agitatethe same of said second con-A tainer and thus produce agitation of theliqiud therein.

4. In a heat exchange device, the combination 0f a container for aliquid, a second container having a heat conducting wall and at leastpartly immersed in said liquid, a tiltable support for said secondcontainer, and means tation to said liquid by causing a adjacent to saidsecond containerto flow altery nately in opposite directions to causesaid second container with its tiltable support to move alternately intodifferent positions, to agitate the con- 4 tents of said secondcontainer.

5. In a heat exchange device, the combination of a. container for aliquid, a second container having a heat conducting wall and extendinginto saidliquid, a pivoted tiltable support arranged in said firstcontainer to receive the bottom of said second container, and agitatingmeans for alternately causing the liquid adjacent to said vsecondcontainer to move in opposite directions in a path substantially atiight angles to the axis of the pivot of said support, to cause saidsecond` container to tilt first inone direction and then for impartingagiportion thereof in another directionto agitate the contents of saidsecond container.

6. In a heat exchange device,\-the combination of a container for aliquid, a second container having a heat conducting Wall and atfleastpartly immersed in said liquid, a tiltable supporfor said secondcontainer, means for imparting agitation to said liquid by causing aportion thereof adja# cent to said second container to flow alternatelyin opposite directions to cause said second container with its tiltablesupport to move alternately into different positions, to agitate thecontents of said second container, and means for limiting the tiltingmovement of said support.

7. In a heat exchangedevice, the combination of a container for aliquid, an oscillatory agitator in said container, a second containerextending into the liquid in said rst container, and means forsupporting said second container in said first container in a manner toenable said second con- Jtainer to oscillate about an axis approximatelyaxis Aof the supportfto cause the movement of the Water to producecorresponding movement of the milk can to agitate the milk.

9. The combination of a tank containing liquid, an agitating paddlearranged in said tank to produce circulation of said liquid, said paddleincluding a coil of pipe through which a tem perature modifying mediummay be passed, and a pair of plates arranged at opposite sides of saidcoil and secured in heat conducting relation to said coil.

10. 'I'he combination of a tank containing liquid, an agitating paddlearranged in said tanku to produce -circulation of said liquid, saidpaddle including a coil of pipe through which a temperature modifyingmedium maybe passed, a pair of plates arranged at opposite sides of saidcoil and secured in heat conducting relation to said coil, means forpivotally supporting said paddle on said tank, and means for moving saidpaddle about said pivot.

11. The combination of a tank containing liquid, an agitating paddlearranged in said tank to produce' circulation of said liquid, saidpaddle including a coil of pipe through which a' temperature modifyingmedium may be passed, the pipe comprising said coil being flattenedintdsubstantially elliptical cross sectional shape, and a plate securedin heat conducting relation to a iiattened face of said pipe.

12. In a milk cooler, the combinatlonof a tank for a cooling liquid, apaddle pivotally mounted on said' tank vto oscillate to producealternating movement of liquid in said tank, means for cooling theliquid in said tank, a support for a milk can pivotally mounted in saidtank to permit a milk can to swing about the pivotal mounting to \alimited extent to produce agitation of the milk i`n\the can, the pivotalaxis of the mounting of said\ support extending substantially parallelto the pivot of said paddle, whereby the paddle causes the\1iquid insaid tank to move relatively to said container, to produce movement ofsaid can about the pivt.\of its support.

13. A heat exchange device including a container'for liquid, a secondcontainer having a wall of heat conducting material and extending intothe liquid in said rst mentioned container, a support in said firstcontainer m which said second container mayvrest, said support beingpivotally arranged with-reference to said rst container to permit saidsecond container to tilt, means for limiting the tilting movement ofsaid support, and means for causing portions of the liquid in said firstcontainer to flow against said second container in a direction' to causesaid sec'- ond container to move about the pivot of said support, toproduce agitation of liquid in said second container.

- 14. A heat exchange device including a container for liquid, acontainer for another liquid movably arranged in said first containerand having imperforate heat conducting walls to prevent mixing of saidliquids, and a paddle arranged in said rst container and movable towardand from said second containerl to -impart movement thereto solelythrough the medium of the liquid in said first container to increase thepassage of heat -from one liquid to the other.

15. A heat exchange device according to claim i 14, `in which the paddlehas mounted thereon a to receive said second container, and a paddlearranged in said first container and movable toward and from said secondcontainer to impart movement thereto solely through the medium of theliquid in said irst container. y

17. A heat exchange device including a container for liquid, a containerfor another liquid movably arranged in said rst container, and asubstantially upright paddle arranged in said rst container and mountedto swing toward and from said second container about an axis arrangedabove the paddle, to impart movement to said second container solelythrough the medium of the liquid in said rst container.

ROBERT K.v DAWSON.' i

